Wiring Plug on 415v 3 Phase Welder

[tshep]

Somewhere there should be a picture, of either a Y or a Triangle.
Triangles use NO neutral, Ys do use a Neutral - at the junction of the Y!
Both still need a ground....
The order only matters for rotation, A, then B, then C, any one can be first if order is eventually the same.
If something rotates backwards, switch any 2 wires.

 

[radios1]

Somewhere there should be a picture, of either a Y or a Triangle.
Triangles use NO neutral, Ys do use a Neutral - at the junction of the Y!
Both still need a ground....
The order only matters for rotation, A, then B, then C, any one can be first if order is eventually the same.
If something rotates backwards, switch any 2 wires.

but also, If it were a 120/240 volt 3 phase 4 wire grounded center tapped Delta red/high leg system also uses a neutral for your 120 Volts. ground should never be used for power..

 

[yomax4]

It's been a while since I wired up a 3ph but If I remember correctly the wire order is on the plug. It's just that the letters on the plug are not the same as the color of the wires. On some welder applications it's just Green is ground and the other don't matter. I don't think the fan will run backward because it's one of the last things to get power. I know my manual says L1 Black, L2 White, L3 Red, Green/Yellow grnd. I'll look at one of my excess 3ph plugs and see what it says.

 

[radios1]

It's been a while since I wired up a 3ph but If I remember correctly the wire order is on the plug. It's just that the letters on the plug are not the same as the color of the wires. On some welder applications it's just Green is ground and the other don't matter. I don't think the fan will run backward because it's one of the last things to get power. I know my manual says L1 Black, L2 White, L3 Red, Green/Yellow grnd. I'll look at one of my excess 3ph plugs and see what it says.

the fan would be single phase. it wouldn't make sense to have a small 3 phase fan in a welder!..

 

[Tractor Seabee]

Separate the various discussions and back to the original question. If the welder only has 3 wires and a ground (green/yellow) then it does not have a neutral so forget that. Not sure what your standard for equipment is in the UK but here there are the NEMA standards for plugs and receptacles to match them up. Yours takes a 4 wire plug/receptacle designed for 460 volts 3 phase. Each voltage, amperage, w/wo neutral so nothing can be mixed up. Here in the US we have 460V non grounded and 480V grounded. Other discussions on how transformers provide those voltages is moot for what you are doing. Problem I see is whether your welder is designed to operate on the lower voltage you have in your system. If it is US made it is a maybe, UK or Europe made probably made for it. Check you mane plate for sure. Low voltage it is not designed for could overheat the windings and or rectifiers. I would bet you are probably OK. If US email the manufacturer and ask them if there is a question. The modern solid state machines will work on many different voltages automatically.

Ron